Firearms

ABSTRACT

A hand held grenade launching gun which is held in both hands for firing has an electrical firing circuit which includes first and second spaced-apart hand operated switching means which are so positioned on the weapon as to be operable only by using both hands, one hand operating the first switching means and the other hand operating the second switching means, the said firing circuit being arranged to fire the grenade when the first switching means is operated at the same time as the second switching means is being operated. The first switching means may include a trigger-actuated tripping mechanism the operation of which momentarily closes an associated electrical switch, and the second switching means may include a resiliently loaded mechanical device, the operation of which closes another electrical switch associated therewith. This invention relates to weapons including missile launchers and more particularly but not exclusively relates to a missile launcher which is held in both hands for firing and which has features of safety to reduce the likelihood of inadvertent firing. Missile launchers, in particular sporting guns, having an electrical firing system have included safety features including the provision of auxiliary or secondary switching means in addition to the primary switching means, which help to avoid inadvertent firing. These guns require operation of both the primary and secondary switching means to fire the gun, but in these known arrangements it has been possible to inadvertently fire the guns using one hand alone, and the secondary switching means has included a switch which is maintained closed after the switching action, the primary switching means being then operable to fire the gun at any later time using only one hand. Accordingly the present invention is directed towards providing a weapon which is fired by simultaneous operation of two switching means, such operation normally requiring the use of both hands of the firer. According to the invention a weapon which is held in both hands for firing has an electrical firing circuit which includes first and second spaced-apart hand-operated switching means which are so positioned that they can only be operated by using both hands, one hand operating the first switching means and the other hand operating the second switching means, the firing circuit being arranged to fire the weapon when the first switching means is operated at the same time as the second switching means is being operated. The first switching means may conveniently include a trigger actuated tripping mechanism, which can be released by operation of a trigger to momentarily close an electrical switch. The second switching means may conveniently include a resiliently loaded mechanical device arranged to close an electrical switch when pressed against the action of a spring. One arrangement of the invention incorporating the tripping mechanism includes a tripping member and a spring, the tripping member being operatively connected to the trigger when cocked against the action of the spring, and so arranged that when released or tripped by the trigger the tripping member momentarily operates, either directly or indirectly, an electrical switch before coming to rest in its release position. Conveniently the fiRst and second switching means have similar resiliently loaded electrical switches which close on application of pressure and open on release of the pressure. The second switching means may include a push button positioned towards the front of the weapon and which can be closed by the forward hand gripping the weapon, and the first switching means may include a finger trigger positioned behind and spaced apart from the second switching means.

United States Patent [191 Brunger et al.

[ Feb. 11, 1975 i 1 F iREARMS [75] Inventors: William Ernest Brunger, Maidstone;

Stanley Gordon Madden, Salisbury;

Benjamin Robinson Sawyer, Cheshunt. all of England [73] Assignee: The Secretary of State for Defence in Her Britannic Majesty 5 Government of the United Kingdom oi Great Britain, London, England [22] Filed: June 15, 1973 [2]] Appl. No.: 370,293

[30] Foreign Application Priority Data June 15, i972 Great Britain 28063/72 [52] US. Cl 42/84, 42/1 F [5i] Int. Cl F4lc 19/12, F4ic 27/06 {58] Field of Search 42/l F, 84

[56] References Cited UNITED STATES PATENTS 2,496,3l6 2/1950 Skinner et al 42/84 3,724,l l4 4/1973 Jones et al, .o 42/84 Primary Examiner-Benjamin A. Borchelt Assistant ExuminerC. T. Jordan Attorney, Agent. or FirmCameron, Kerkam. Sutton. Stowell & Stowell [57] ABSTRACT A hand held grenade launching gun which is held in both hands for firing has an electrical firing circuit which includes first and second spaced-apart hand 0perated switching means which are so positioned on the weapon as to be operable only by using both hands. one hand operating the first switching means and the other hand operating the second switching means, the said firing circuit being arranged to tire the grenade when the first switching means is operated at the same time as the second switching means is being operated.

The first switching means may include a trigger-actuated tripping mechanism the operation of which momentarily closes an associated electrical switch. and the second switching means may include a resiliently loaded mechanical device, the operation of which closes another electrical switch associated therewith.

8 Claims, 8 Drawing Figures FIREARMS This invention relates to weapons including missile launchers and more particularly but not exclusively relates to a missile launcher which is held in both hands for firing and which has features of safety to reduce the likelihood of inadvertent firing.

Missile launchers, in particular sporting guns, having an electrical firing system have included safety features including the provision of auxiliary or secondary switching means in addition to the primary switching means, which help to avoid inadvertent firing. These guns require operation of both the primary and secondary switching means to fire the gun, but in these known arrangements it has been possible to inadvertently fire the guns using one hand alone, and the secondary switching means has included a switch which is maintained closed after the switching action, the primary switching means being then operable to fire the gun at any later time using only one hand.

Accordingly the present invention is directed towards providing a weapon which is fired by simultaneous operation of two switching means, such operation normally requiring the use of both hands of the firer.

According to the invention a weapon which is held in both hands for firing has an electrical firing circuit which includes first and second spaced-apart handoperated switching means which are so positioned that they can only be operated by using both hands, one hand operating the first switching means and the other hand operating the second switching means, the firing circuit being arranged to fire the weapon when the first switching means is operated at the same time as the second switching means is being operated.

The first switching means may conveniently include a trigger actuated tripping mechanism, which can be released by operation of a trigger to momentarily close an electrical switch.

The second switching means may conveniently include a resiliently loaded mechanical device arranged to close an electrical switch when pressed against the action of a spring.

One arrangement of the invention incorporating the tripping mechanism includes a tripping member and a spring, the tripping member being operatively connected to the trigger when cocked against the action of the spring, and so arranged that when released or tripped by the trigger the tripping member momentarily operates, either directly or indirectly, an electrical switch before coming to rest in its release position.

Conveniently the first and second switching means have similar resiliently loaded electrical switches which close on application of pressure and open on release of the pressure.

The second switching means may include a push button positioned towards the front of the weapon and which can be closed by the forward hand gripping the weapon, and the first switching means may include a finger trigger positioned behind and spaced apart from the second switching means.

An example of the invention will now be described with reference to the drawings in which:

FIG. 1 is a vertical axial section of a grenade launcher, when cocked ready for firing.

FIGS. 1A, 1B and 1C are enlarged vertical axial sectional views of the forward, middle and rear portions, respectively, of the launcher shown in FIG. 1.

FIG. 2 is a plan view of the launcher, part shown in section.

FIG. 3 is a view of part of the launcher shown in FIG. 1, with the tripping mechanism in the release position.

FIG. 4 is a sectioned view of part of a grenade suitable for firing from the grenade launcher.

FIG. 5 is a view on V V ofof FIG. 4. FIG. 6 is an enlarged detail view on VI VI of FIG. 1 showing part of the first switching means of the launcher.

The drawings illustrate a grenade launcher which causes an electric current to initiate an explosive conducting composition in the grenade to discharge the grenade from the launcher. The launcher is designed to discharge canister grenades, which may include gas, smoke or other antipersonnel grenades.

The launcher has a barrel 1 at its forward end, into which a grenade (partly shown in FIGS. 4 and 5) can be loaded, and from which it can be fired. The barrel 1 is a sliding fit on the outer surface of a cylindrical cover 2 which is welded to an elongated cylindrical body 3 of the launcher, the body also having an externally threaded tubular portion 3a rigidly fixed to its forward end. The barrel 1 has a circular backplate 43 the circumference of which conforms to the internal diameter of the barrel, and which has a coaxial internally threaded spigot 43a screwed onto the portion 3a of the body 3. The barrel 1 is retained on the cover 2 by means of two hollow buttons 12, 13 (FIG. 2) mounted in cover 2 and spring loaded by respective helical springs 14, 15 located within the buttons 12, I3 respectively. When the barrel is fitted onto the cover 2 the buttons l2, 13 are arranged such that by the action of the respective springs they are, when correctly aligned, urged outwardly to engage diametrically opposed holes 16, 17 in the cover 2 of the launcher, as shown in FIG. 2. The protrusion of the buttons is limited by circlips 18, 19 fitted to the respective buttons l2, 13 within cover 2.

A butt 4 of the launcher, comprises a foam backed curved butt plate 5 welded to a butt cylinder 6 which is a sliding fit inside the rear of the body 3 of the launcher. The butt cylinder 6 is retained and located in the body of the launcher by means of a hollow button 7 at the forward end of the butt cylinder, which is spring loaded by a helical spring 8 positioned inside the button 7 and compressed between the button and a housing 9 in which the button is mounted. When the butt 4 is inserted into the rear of the body 3 and correctly aligned the button is urged by the action of the spring 8 into engagement with a hole 10 in the body 3 of the launcher as shown in FIG. 1. The protrusion of the button 7 is limited by a circlip 11 mounted in a groove in the button.

A box-shaped tripping mechanism guard 20 (FIG. I) is welded to the outside of the cylindrical body 3 at about the midpoint of the length of the launcher, on one side of the launcher, hereinafter referred to as the lower side of the launcher. The guard 20 includes a substantially cylindrical hollow support bracket 21 mounted with its axis perpendicular to the axis of the body 3. A tripping member comprising a trip rod 22 shown in the cocked position in FIG. 1, and in the release position in FIG. 3, is mounted with its axis parallel to the axis of the body 3 and extends through a support bracket 23 welded to the guard 20 and located in a hole in the front end thereof, and through a hole in the support bracket 21 perpendicular to its longitudinal axis.

A helical trip spring 24 which together with the trip rod 22 comprises the tripping mechanism is mounted and compressed on the rod 22 between the support bracket 21 and a step 25 in the rod. The rod 22 has a notch 26 on its lower side, and a pair of spaced curved recesses 27, 28 on the diametrically opposite side of the rod. The purpose of the curved recesses 27, 28 will be described later. A trigger 29 which is rotatably mounted on the guard by means of a pin 30, has a detent 31 designed to fit into the notch 26 of the trip rod 22 when the tripping mechanism is cocked as illustrated in FIG. 1. The trigger 29 extends through a slot in the lower face of the tripping mechanism guard 20.

A pistol grip 32 is fixed to the body 3 of the launcher by means of a threaded bolt 34 which screws into the support bracket 21 of the tripping mechanism guard 20. The pistol grip 32 has a trigger guard 35, one end of which is fitted by a screw 38 into the pistol grip and the other end fits into a slot in the lower face of the tripping mechanism guard 20.

A trigger return plunger 36 is mounted in the pistol grip 32 behind the trigger 29, and is spring loaded by a helical spring 37 located in a recess in the pistol grip 32. The plunger 36 acts on the trigger 29 to urge the detent 31 into contact with the trip rod 22.

At the forward end of the launcher a hand operated push button 39 is welded to the body 3 and cover 2 on the same lower side of the launcher as the tripping mechanism guard 20. The push button comprises a hollow cap 40 screwed onto a plunger 41 which passes through a guide mounted in the cover 2 and body 3 of the launcher. A helical spring 42 is positioned on the plunger 41 within the cap 40. The push button 39 is operated by upward pressure on the cap 40 against the re silience of the spring 42 and on release of the pressure the plunger is returned by the spring 42 to the position illustrated in FIG. 1, and is retained in the body by a flange at its inner end.

Two electrical switches in the form of microswitches 44, 45 are rigidly fixed in a housing 46 by means of bolts 49, 50 and 47, 48 respectively which extend through the width of the housing. The microswitches 44, 45 have resiliently loaded operating buttons 80, 81 respectively and are of the kind which are operated by applying pressure on the respective operating buttons to make an electrical contact against the action of a spring, the switch being opened upon release of the pressure which causes the spring to break the electrical contact. The housing 46 is in the shape ofan elongated box with open ends and an open lower side adjacent the push button 39 and tripping mechanism guard 20. An insulator block 51 is fixed into the rear end of the housing 46 by means of bolts 52, 53 which extend through the width of the housing. The housing 46 is fixed inside the body 3 in such a position that the operating button 80 of the microswitch 44 is in line with the curved recess 27 when the tripping mechanism is cocked and in line with the curved recess 28 when the tripping mechanism is in the release position (FIG. 3), and the operating button 81 of microswitch 45 is in line with the plunger 41 of the push button 39. The housing 46 is located in the body 3 by means of a locating screw 54 which is screwed into the insulator block 51 of the housing through the support bracket 2] of the tripping mechanism guard 20, and by means of a set screw 88 which is mounted in the cover 2 and body 3 and engages and locates the forward end of the housing 46.

A switch actuator 74, illustrated in FIG. 1, 3 and 6, comprises a spring arm rigidly attached to the microswitch 44 by the bolts 49 and 50. The free end of the spring arm 75 is positioned directly below the operating button of the microswitch 44 (FIGS. 1 & 3) and has, pivotly mounted thereon, one end of an arm 76. The arm 76, which has a roller 77 at the other end, is urged toward the vertical position shown in FIG. 1, by a spring 83 (FIG. 6) mounted on the spring arm 75 which tends to rotate the arm 76 and roller 77 in the clockwise direction in FIGS. 1 & 3, in a plane parallel to the axis of the body 3 of the launcher, about the free end of the spring arm 75 directly below the operating button 80 and into engagement with a stop plate 78 which prevents clockwise rotation beyond the vertical position illustrated.

The insulator block 51 has a hole through its centre parallel to the axis of the body 3, in which hole is positioned a rigid electrical conductor 55 which has a spring-loaded contact 56 at its rear end. The contact 56 extends under the action of the spring slightly beyond the rear of the insulator block 51 and makes contact with one of a pair of dry cell batteries 57, inserted into the rear end of the body 3 and urged forwardly to compress the spring-loaded contact 56 by a helical spring 58 fixed in an internal recess in the butt cylinder 6.

The electrical firing circuit connects the batteries 57 through the contact 56, rigid conductor 55 and an insulated lead 59 to the microswitch 44. An insulated lead 60 extends from the microswitch 44 to the microswitch 45, which is electrically connected to a spigot 62 via a further insulated lead 61 and a rigid conductor 63. The spigot 62 is located at the forward extremity of a substantially hollow cylindrical extension plug 64 which is a slide fit in a bore through the centre of the back plate 43. The rigid conductor 63 is located within the forward part of the plug 64 and is electrically insulated therefrom by means of two plastic bushes 65, 66. The plastic bush 65 also insulates the spigot 62 from the plug 64. The rearward end of the plug 64 has a flange, shown in FIG. 2, with diametrically opposed flats ground to the external diameter of the plug, forming the flange into two parts 86, 87. When the backplate 43 is screwed onto the body 3, the parts 86, 87 of the flange at the rear of the plug 64 are arranged to fit into slots 84, respectively, one in each side of the housing 46 at its forward end.

A grenade for firing from the launcher has, at its rear end, an adaptor designed to fit over the plug 64 in the barrel 1, so that the electrical firing circuit can be made through the explosive conducting composition in the grenade from the spigot 62 to the plug 64. The firing circuit is completed through the body 3 of the launcher, the butt cylinder 6 and helical spring 58 to the rear of the batteries 57.

The grenade has an adaptor as illustrated in FIGS. 4 and 5 designed to fit over the plug 64 and spigot 62 protruding from the barrel backplate 43. The adaptor has a recess 67 within which is mounted two spring clips 68 and 69 electrically connected to each other through the explosive conducting composition. Each spring clip has two opposed arms, each pair of arms forming a throat 70, 71 respectively, the throats being spaced longitudinally along the axis of the grenade. When the grenade is loaded into the launcher the spring clips fit over the plug 64 and spigot 62 with the throat 71 of the clip 69 making electrical contact with the spigot 62 and the throat 70 of the clip 68 making electrical contact with the plug 64.

As a safety precaution, when the launcher is not in use, the tripping mechanism should always be in the release position, as shown in FIG. 3. The position of the tripping mechanism can be ascertained by visual inspection of the front of the trip rod 22, a substantial part of the rod 22 protruding from the front of the guard 20 being an indication that the tripping mechanism is in the release position, as shown in FIG. 3.

To operate the launcher a grenade is inserted into the open end of the barrel 1 and the grenade adaptor engages the plug 64 and spigot 62. When ready to fire the launcher, the tripping mechanism is cocked by pushing the trip rod 22 in the rearward direction of the launcher into the guard 20, compressing the helical spring 24 until the detent 31 of the trigger 29 engages the notch 26 of the rod. The trigger return plunger 36 and helical spring 37 ensure that the detent 31 is constantly urged into the notch 26, so that the detent will retain the trip rod 22 in the cocked position illustrated in FIG. 1. When the trip rod is in the cocked position the curved recess 27 is located directly below the roller 77 of the switch actuator 74 which is itself positioned directly below the operating button 80 of the microswitch 44. To hold the launcher in the firing position the butt 4 is placed against the shoulder, the pistol grip 32 is held in one hand and the cover 2 and rear portion of the barrel 1 are gripped in the other hand, so that the palm of that hand rests in contact with the push button 39. The launcher is fired by tightening the grip on the cover 2 and rear portion of the barrel so that the palmof the gripping hand operates the second switching means by pushing the cap 40 and plunger 41 upwards to close the microswitch 45. Whilst maintaining the grip to keep the microswitch 45 closed, the first switching means is operated by pulling the trigger 29 with the hand holding the pistol grip thus causing the detent 31 to rotate in an counterclockwise direction and disengage from the notch 26 to release the trip rod 22. Under the action of the compressed helical spring 24 the trip rod 22 moves rapidly forward, and the part of the rod between the curved recesses 27, 28 acts on the roller 77 to lift the switch actuator 74. The stop plate 78 prevents the arm 76 and roller 77 from rotating about the free end of the spring arm 75 and the switch actuator is forced upwards against the action of the spring arm 75 to depress the operating button 80 and close the microswitch 44.

The operation of the first switching means at the same time as the second switching means completes the firing circuit which causes a current to flow from the plug 64 to the spigot 62 through the explosive conducting composition in the grenade to fire the launcher.

The trip rod 22 moves under the action of the helical spring24 until a circlip 82 positioned in a groove at the rear end ofthe rod engages a countersink 73 in the support bracket 2]. The countersink 73 and circlip 82 are so arranged that when the circlip 82 engages the countersink 73 to halt the trip rod 22 at its release position, the switch actuator has moved from the part of the rod between the curved recesses 27, 28 and under the action of the spring arm 75 disengages from the operating button 80 and enters the curved recess 28. The microswitch 44 closes to complete the firing circuit only for as long as upward pressure is maintained against the operating button 80 of the microswitch 44 by the switch actuator 74. The microswitch is thus closed only for the very short period of time that the microswitch actuator 74 is pushed upward by the part of the rod between the curved recesses 27, 28. This period of time is governed by the strength of the helical spring 24, and the length of the part of the rod between the curved recesses 27, 28.

The actuator switch 74 will only close the microswitch 44 as the trip rod moves forward after being released from the cocked position. When the tripping mechanism is being cocked by pushing the rod, in the rearward direction of the launcher against the action of the spring 24, the part of the rod between the curved recesses 27, 28 again comes into contact with the roller 77 of the switch actuator 74, but merely serves to rotate the arm 76 about the free end of the spring arm thus preventing the switch actuator from making contact with the operating button 80 and thus prevent ing the closure of the microswitch during the operation of cocking the launcher.

Although the second switching means can be operated for as long as the grip is retained on the forward end of the launcher, the first switching means can only be operated momentarily, making it normally impossible for the firing circuit to be maintained completed for any appreciable length of time, and hence reducing the danger that the firing circuit may be completed as the grenade is fitted onto the plug 64 and spigot 62 in the barrel 1 of the launcher.

The trigger 29 of the first switching means and the push button 39 of the second switching means are so spaced apart on the launcher that it is virtually impossible to operate the first and second switching means and hence fire the launcher with one hand. The trigger 29 and push button 39 are arranged and located so that each must be operated by a different hand of the user, when the launcher is held in the naturally convenient position with the butt against the shoulder with the pistol grip in one hand and the other hand supporting the barrel 1.

The launcher described with reference to the drawings can be readily dismantled or assembled as required. The butt 4 can be dismantled, for instance to replace the batteries 57, by simply pushing the push button 7 and pulling the butt 4 from the rear end of the body 3 of the launcher. The barrel 1 is similarly re moved by operating the push buttons 12 and 13. The microswitch housing 46 is pre-assembled with the microswitches 44, 45, conductor 55, electrical leads 59, 60, 6] insulator block 51 and contact 56, and is inserted into the body generally at an early stage of assembly. The tripping mechanism can be removed from the launcher by removing the circlip 82 and pulling the rod in a forward direction whilst maintaining a pull on the trigger 29.

The launcher hereinbefore described can only be operated or fired by performing three separate operations, namely the cocking of the tripping mechanism and the simultaneous operation of the switching means. each of the last two being operated by a different hand, thus considerably reducing the possibility of inadvertent firing.

Although the invention has been described in relation to a grenade launcher it can also be applied to other weapons, such as guns and rifles, having an electric firing circuit.

We claim:

l. A firearm which is held in both hands for firing having an electrical firing circuit which includes first and second spaced-apart hand operated switching means which are so positioned on the firearm as to be operable only by using both hands, one hand operating the said first switching means and the other hand operating the said second switching means, the said firing circuit being arranged to fire the firearm when the first switching means is operated at the same time as the second switching means is being operated, the said first switching means including a tripping mechanism. a trigger by means of which the tripping mechanism is actuable and an associated electrical switch forming part of the electrical firing circuit and arranged to be momen' tarily closed by said tripping mechanism when the latter is actuated by operation of the trigger.

2. A firearm as claimed in claim 1 in which the tripping mechanism includes a tripping member and an associated spring, which tripping member is engageable by the said trigger to hold it cocked against the action of its spring, and moveable under action of its spring when released by operation of the trigger to momentarily close the said associated electrical switch before coming to rest in its release position.

3. A firearm as claimed in claim 1 wherein the said trigger is operable by finger pressure and is positioned behind and spaced apart from the said second switch ing means.

4. A firearm as claimed in claim 1 in which the said second switching means includes a pressure member loaded by a spring and arranged to close an associated electrical switch when pressed against the action of the spring.

5. A firearm as claimed in claim 4 in which the said second switching means includes a push button loaded by a spring positioned towards the front of the firearm which push button may be pressed against the action of the spring when the forward hand grips the firearm.

6. A firearm as claimed in claim 1 in which at least one of the first and second switching means has an associated pressure operated resiliently loaded electrical switch which closes on application of pressure and opens on release of the pressure.

7. A hand held grenade launcher gun consisting of a firearm as claimed in claim 2 having a body, a barrel at the forward end of the body into which barrel a grenade may be loaded and from which it may be fired, and a butt at the rear of end of the body; the said second switching means being located adjacent the barrel and the first switching means being located adjacent the butt of the gun.

8. A hand held grenade launcher gun as claimed in claim 7 having a pistol grip mounted on the body, and a trigger carried by the pistol grip for operating the said first switching means.

i l l UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION- PATEN'Y NO. I 3,864,862

DATED I Feb. ll, 1975 |NVENTO I William Ernest Brunger et al.

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below;

Cover page, item [73] should read:

-Assignee: The Secretary of State for Defence in Her Brittanic Majesty's Government of the United Kingdom of Great: Britain and Northern Ireland, London England- Claim 7, line 2, "2" should read -l.

Signed and sealed this 20th day of May 1975.

(SE Attest:

C. MARSHALL DANN RUTH C. MASON Commissidner of Patents Attesting Officer r and Trademarks UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,864,862

DATED 1 Feb. ll, 197-5 INVENTO I William Ernest Brunger et al.

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below;

Cover page, item [73] should read:

-Assignee: The Secretary of State for Defence in Her Brittanic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland, London, England-- Claim 7, line 2, "2" should read --l--.

Signed and sealed this 20th day of May 1975.

(SEAL) Attest:

C. MARSHALL DANN RUTH C. MASON Commissioner of Patents Attesting Officer and Trademarks UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENY NO. 3,864,862

DATED 11, 1975 INVENTOR(S) 1 William Ernest Brunger et al.

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below.

Cover page, item [73] should read:

--Assignee: The Secretary of State for Defence in Her Brittanic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland, London, England-- Claim 7, line 2, "2" should read --l.

Signed and sealed this 20th day of May 1975.

(SEAL) Attest:

C. MARSHALL DANN RUTH C. MASON Commissioner of Patents Attesting Officer and Trademarks 

1. A firearm which is held in both hands for firing having an electrical firing circuit which includes first and second spacedapart hand operated switching means which are so positioned on the firearm as to be operable only by using both hands, one hand operating the said first switching means and the other hand operating the said second switching means, the said firing circuit being arranged to fire the firearm when the first switching means is operated at the same time as the second switching means is being operated, the said first switching means including a tripping mechanism, a trigger by means of which the tripping mechanism is actuable and an associated electrical switch forming part of the electrical firing circuit and arranged to be momentarily closed by said tripping mechanism when the latter is actuated by operation of the trigger.
 2. A firearm as claimed in claim 1 in which the tripping mechanism includes a tripping member and an associated spring, which tripping member is engageable by the said trigger to hold it cocked against the action of its spring, and moveable under action of its spring when released by operation of the trigger to momentarily close the said associated electrical switch before coming to rest in its release position.
 3. A firearm as claimed in claim 1 wherein the said trigger is operable by finger pressure and is positioned behind and spaced apart from the said second switching means.
 4. A firearm as claimed in claim 1 in which the said second switching means includes a pressure member loaded by a spring and arranged to close an associated electrical switch when pressed against the action of the spring.
 5. A firearm as claimed in claim 4 in which the said second switching means includes a push button loaded by a spring positioned towards the front of the firearm which push button may be pressed against the action of the spring when the forward hand grips the firearm.
 6. A firearm as claimed in claim 1 in which at least one of the first and second switching means has an associated pressure operated resiliently loaded electrical switch which closes on application of pressure and opens on release of the pressure.
 7. A hand held grenade launcher gun consisting of a firearm as claimed in claim 2 having a body, a barrel at the forward end of the body into which barrel a grenade may be loaded and from which it may be fired, and a butt at the rear of end of the body; the said second switching means being located adjacent the barrel and the first switching means being located adjacent the butt of the gun.
 8. A hand held grenade launcher gun as claimed in claim 7 having a pistol grip mounted on the body, and a trigger carried by the pistol grip for operating the said first switching means. 